Signal



ot. 23, 1934. ADLER, JR 1,978,334 L SIGNAL Filed April 26, 1934 Patented Oct. 23, 1934 UNITED STATES PATENT OFFICE SIGNAL 7 Charles Adler, Jr., Baltimore, Md. I A l Application April 2s, 19s4, Serial No. 722,5 3 7 9 Claims. (01. 177 -329) I 7 My invention relates to light signals and will materially increase their safety factor and reduce the, possibility of train delays caused by failure of the source of illumination. l p 1 Thepresent signal while particularly useful in railroad signaling is applicable to practically all conditions where traffic control and direction are necessary;

The almost universal use of'light signals by the railroads of this country-has brought to the fore the problem ofguarding against failure of the incandescentqsource "of illumination; -When a failure of this'naturesoccurs, two undesirable conditions are created: First; thepossibility of a: delay to train movements and second-the .po-

tential danger of an enginer'nans failure to see the signal in its unlighted conditio l 1 When the electricsla'mp which illuminates the lens and' displays the signal burns out,I provide means whereby the signal will be maintained operative and directive to the engineman and at the same time'will enable the maintainer to observe the failure. I f Of particular importance I provide means whereby in the event of a failure, the lens will be illuminated in such a manner that the signal will be clearly, and definitely observable to the engineman without possibility of confusion. The present signal utilizes a 'multiplicity of lamps; one of which is in focus with the signal lens or cover glass for normally fullyilluminating the same, and'a second lamp which is screened from the signal lens except at the area comprehended by a smaller lens disposed between the lamps and in focus with the second lamp. Should, therefore, the main lamp which illuminates the signal lensbe extinguished, the second lampin cooperation with the second lens will illuminate. the signal producing an illuminated central spot of such intensity as to be readily observable by theengineman and at the same time the area of the signal lens surrounding the central spotwill be darkened sothat the "maintenance man will observe the fault.

Referring to the drawing: i Figure 1 isasectional view showing my improved signal unit. i Figure 2 is a front elevation showing the appearance of thesignal lens when'the main lamp hasbeenextinguished, and

' Figure3 is a front elevation of a positionlight dwarf signal.

Referringto Figure 1, I have shown thesignal unit of1my invention as comprising a housing 10, a signal lens 11 or cover glass,; and a hood 12.

It will be understood that as'many units will be employed as there are signal lenses. 7 g j l These units when employed in a position light dwarf signal, as shown in Figure 3, are disposed in a large casing suitably partitioned to form a lamp housing in' association with eachlens. M

It will beobservedthat the signal lens '11 is concavo-convex and on its concave side is stepped as shown at 13 in the form of a multiplicity of concentric steps of progressively reduced l I preferably employ two electric lamps 14 and 15 which are spacedapart in longitudinal alignment with respect to the signal lens 11, thatis, the filaments of the respective lamps are axially aligned. r

The lamp 151 or main lamp is in focus with the signal lens 11 and is relied upon to normally illuminatethe lens. The lamp 15 I will call the secondary or auxiliary lamp and of the two is disposed remote from the signal lens. r

, Disposed between the lamps is a partition 16 of opaque material which divides the chamber into two sections. The partition 16 constitutes a shield for light emitted by the lamp.l5, and carried by this shield 16 is a convex lens 17, which as shown is disposed between the lamps 14 and and in rear of the lens or cover glass 11. This lens is in focus with the lamp 15. By reason of this construction, the signal lens 1'7 is completely shielded fromthe lamp 15 except at the area comprehended by the convex lens 17. r

This convex lens may be of any desired peripheral contour, butis preferably circular and is in axial alignment with the signal lens 11. As shown, the lens-17 is of relatively small diameter with respect to the signal lens 11. The lens 17 is powerful enough to project and concentrate beams of light from the lamp 15 upon thesignal lens to give aclear and distinct illumination of the central portion of thesignal lens as will be later more fully described;

The shield 16 is supported at its lower end by a bracket 18 bolted at 19 to the wall of the casing 10, said shield having an angle member '20 which is bolted to the bracket 18 as at 21. The angle member 20 and bracket 1''? extend entirely across" the housing so as to cooperate with the shield 16. V r

Carried by the shield 16 upon opposite sides thereof and at a point'so that'the main and secondary lamps will be respectively focussed with the signal lens 11- and the convex lens 17, as

described above, are brackets 22 connected to, the

shield by screws 23 and carrying lamp sockets 22, the shield 16, and the Wire 28 which. iselectrically connected to the shield as shown at 29.

It will be observed, therefore, that I have pro vided two light sources electrically connectedin parallel with one light source shielded from the signal lens except in the area comprehended by i the convex lens 17.

The lamps 14 have filaments of'substantially equal intensity and capacity, and it is recognized.

that no two lamps will have the same life. Con sequently, one of the lamps will be extinguished before the other. 'In'the initial installation of the signal the lamp 14 will preferably be a lamp which has had more hours of use than the lamp 15 and hence, the lamp 14 will be extinguished first, it being understood, of course that both lamps 14 and 15 will simultaneously-be illuminat'ed. -When the lamp 14 burns out the lamp 15 is moved to its place and a new lamp provided for the auxiliary or secondary lamp;

The lamp 14, as stated, is the main lamp, and is relied upon for normally illuminating the signal lens 11 with whichit is'in focus. However, if the lamp 14 is extinguished for any reason then the lamp 15 in cooperation with the lens 1'7 will display on the signal lens a central spot of such clarity and intensity as to be observed and accepted as directive by the engineman. This is due to the fact that the lenses are in axial alignment and the lamp 15 is in focus with the lens 1'7. Referring to Figure 1, the lines 30 indicate the manner in which light beams from the lamp 15 are projected and concentrated by the lens 17. The light produced by the lamp 15in cooperation with the convex lens 17 upon the signal lens-forms a central brilliant spot 31 on the signal area or lens 11, as shown in Figure 2, and also results in a surrounding darker area 32. This spot'31, as stated, displays the signal area so that it is observable and acceptable by the engineman as a signal, while the; dark area 32 is at once indicative to the maintenance man that the main lamp 14 has failed. a

It is important in connection with position light dwarf signals particularly, that the illumination of the signal lens 11 be definite, becausein such installation the engineman relies for his indication upon a horizontal, diagonal or vertical row of two lights, as shown in Figure 3( When one of these lights fails the signalindication is obviously lost, with resulting train delays. With the present invention, however, the central spot is so clear and definite as to avoid any confusion on the part of the engineman. l

I claim:

1. A signal comprising a cover glass or lens constituting a signal area and electrical illuminating means therefor, means comprising a second lens and electrical illuminating means for producing contrasting light and dark areas on the signal area when the first illuminating means is extinguished, the said cover glass or lens and said second lens being disposed one in rear of the other, said illuminating means being each norilluminated and adapted to illuminate the signal area.

3. A signal comprising a cover glass or lens constituting a signal area and electrical illuminating means therefor, means comprising a second lens and electrical illuminating means for producing contrasting light and dark areas on the signal area when the firstilluminating means is extinguished, said second mentioned lens being of less area than said signal area, the said cover glass or lens and said second lens being disposed one in rear of the other, said illuminating means being each normally simultaneously illuminated and adapted to illuminate the signal area.

4. A signal comprising a cover glass or lens constituting a signal area and electrical illuminating means therefor, means comprising a second lens and electrical illuminating means for producing contrasting light and dark areas on the signal area-when theifirst illuminating'means is extinguished and including means for shielding said last mentioned illuminating means from said signal area except in the area comprehended by said second lens, the said cover glass or lens and saidv second lens being disposed one in rear of the other, said illuminating means being each normally simultaneously illuminated and adapted to illuminate the signal area.

5. A signal comprisinga cover glass or lens constituting a signal area and electrical illuminating means therefor, means comprising a second lens and electrical illuminating means for producing contrasting light and dark areas on the signal. area when the first illuminating means is extinguished, the said cover glass or lens and said second. lens being concentrically disposed one in rear of the other, said illuminating means being each normally simultaneously illuminated and adapted to illuminate the signal area.

6. A signal comprising a cover glass or lens constituting a signal area and electrical illuminating means therefor, means comprisingasecond lens and electrical illuminating means for producing contrasting light and dark areas on the signal area when the first illuminating means is extinguished, said first mentioned illuminating means being in focus with said lens or cover glass and said second mentioned illuminating means being in focus with said second mentioned lens, thev saidcover glass or lens and said second lens being disposed one in rear of the other, said illuminating means being each normally simultaneously illuminated and adapted to illuminate the signal area.

' 7. A signal comprising a cover glass or lens constituting a signal area and electrical filamentary illuminating means therefor, means comprising a second lens and electrical filamentary illuminating means for producing contrasting light and dark areas on the signal area when the first illuminating means is extinguished, the said cover glass or lens and said second lens being til disposed one in rear of the other, said illuminating means being each normally simultaneously illuminated and adapted to illuminate the signal area.

8. A signal comprising a cover glass or lens constituting a signal area and electrical illuminating means therefor, means comprising a secand lens and electrical illuminating means for producing contrasting light and dark areas on the signal area when the first illuminating means is extinguished, said illuminating means comprising filaments, one in focus with said lens or cover glass and the other in focus with said second lens respectively, the said cover glass or lens and said second lens being concentrically mounted 

